1. Field of the Invention
The invention concerns a bus bar laterally equipped with flat tabs formed in one piece, of the comb type having connector plug sockets, the connector plug sockets having at least one pair of elastic arms, which receive a supplementary contact and an applicator spring. Such bus bars are used, in particular, in the installation of electrical power networks through which pass currents of an intensity of the order of up to 100 A, under a voltage of some hundreds of volts. The invention is applied everywhere where electrical power energy of up to 100A per contact must be distributed.
2. Brief Description of Related Developments
A bus bar of this type is, according to the preamble, in known from, for example, patent application EP 814 551 A1. In such bus bars, when the line serves for the passage of high intensity currents of up to several amperes, the problem arises of very strong heating up of the bus bar if a current of that order is passed into a plate formed of one layer. If these bus bars are placed in switching boxes, this can easily lead to undesirable overheating in the said switching boxes.
To pass higher current intensities, the bus bar can be connected to other electrically conducting layers, which are fixed to the bus bar. This, however, complicates the manufacture of the bus bar, owing to the fact that the additional layers must be fixed to the bus bar.
The purpose of the present invention is that of providing a bus bar, which only undergoes slight heating up, even when high current intensities pass through it and which is of a simple design and therefore easy to manufacture.
The problem is solved by the fact that the bus bar with flat tabs is made from two layers and that one of the arms of the said pair of elastic arms is formed in one piece onto each layer of the bus bar. Thanks to this two-layer construction of the bus bar, the section serving for the passage of electricity is of double size and is able to pass higher current intensities of up to 100 amperes, without attracting a high degree of heating up of the bus bar. Also, the assembly of the bus bar with connector plug sockets is facilitated. Until to the present, in order to pass higher intensities through a multi-layer construction of the bus bar, it was necessary to provide rivets in order to interconnect the multi-layer bus bar, but in the present invention, the multi-layer bus bar is assembled solely by the action of the applicator spring. The assembly of rivets or similar fixing devices is not absolutely essential.
According to a preferred form of embodiment, the two flat tabs of a plug connector socket together form a bottom plate of the connector plug socket. This bottom plate has the advantage of having a double thickness in opposition to the bus bar in the preamble. For this reason, it is possible to better pass currents from the connector plug socket to the bus bar.
The two elastic arms of the said pair of elastic arms are preferably inclined towards one another on emerging from the bottom plate and then continuing by drawing aside in the form of a funnel. Moreover, the applicator spring customarily has a number of elastic arms equal to the number of pairs of elastic arms. The applicator spring brings together the ends, which continue in the form of a funnel, by pressing them together with the pairs of elastic arms and thus increases the normal strength of contact applied a blade contact inserted into the connector plug socket.
According to a preferred form of embodiment, the applicator spring has a connection plate equipped with lugs, with the help of which the two flat tabs of a connector plug socket are interconnected and with the help of which the applicator spring is connected to the pair of elastic arms. Thanks to these applicator spring lugs the bus bar is connected to two layers.
Moreover, one of the two contact bus bars has on the outside of the connector plug socket, lugs with the help of which the two layers of the bus bar are interconnected. In order to secure a better connection between the two layers, it is possible to make a rigid connection outside the lugs of the applicator spring by means of the lugs which are provided on the edge of one of the bus bar layers and come into contact with the edge of the second bus bar layer.
Preferably, the two layers of the bus bar are arranged substantially in parallel. For that reason, the two flat tabs, which constitute the bottom plate of the connector plug socket, come into contact with one another over a large surface, facilitating the passage of current between the two layers of the bus bar.
Preferably, the two layers of the bus bar are interconnected without brasing and/or welding. As already stated earlier, the connection between the two layers is principally made by the applicator spring, which holds together the two contact arms of a connector plug socket placed against one another and are formed in one piece onto the two different layers of the bus bar.
According to another form of embodiment of the bus bar according to the invention, the two layers of the bus bar can be interconnected by means of an adhesive plate, arranged between the two layers. This adhesive plate is sticky on the upper face and the lower face. This adhesive plate is not usually conductive, whilst the two layers of the bus bar are at the same potential. This is the result, firstly of the fact that the inserted blade contact comes into contact with the two pairs of elastic arms, each belonging to a different layer of the bus bar and secondly of the fact that the plates can be interconnected in an electrically conducting manner by means of rivets, or a common supply at the ends opposite the conductors, providing simultaneous distribution to the two plates, the current distributing itself in a balanced manner in the two plates.